Medela's swing pump is the smallest and lightest single electric breast pump on the market. This easy to use, quiet pump allows you to spend less time pumping and more time on what matters. Swing is designed for occasional use and offers a battery operated option, making it ideal for moms on the go or for moms who want to pump while nursing. Swing features Medela's patented 2-phase expression technology, scientifically proven to produce more milk in less time. Comes with Medela's calma nipple, scientifically proven to make switching from breast to calma and back a breeze. All parts that touch breastmilk are made without BPA, DEHP and other phthalates. Included: 1 x calma nipple, 2 x 150 ml bottles with lids (BPA-free), 2 x personalfit breast shields (Standard size 24 mm), 1 x drawstring carrying bag. *Why is Medela's patented 2-phase expression technology important? Research shows that babies feed with two distinct phases. Stimulation phase, when babies first go to breast, they suck faster to start the milk flowing. Expression phase, after milk flow or let-down" starts, babies breastfeed with a slower, deeper suck to remove milk. By mimicking this behaviour, Medela's patented 2-phase expression technology is proven to produce more milk in less time when pumping at maximum comfort vacuum in the expression phase. For hygienic reasons, breast pumps cannot be returned once opened. This is a single user product. Use by more than one person may present a health risk, affects performance, and voids the warranty."